of semi-finished products
Extruded tubes in straight lengths or in coils are used as prematerials. A differentiation is made between porthole- and mandrel extruded tubes. In some cases, welded tubes are also used as pre materials, and with copper, pre drawn tubes are already used occasionally.
Some extruded tubes require an initial annealing process in order to facilitate drawing. That is why an initial annealing process is carried out before drawing.
Pointing is the first step in processing; a tip is formed by which the tube can be drawn through the tool. In case of larger diameters, tubes are held with interior collets. During the production of coils, the tube only needs to be pointed at the beginning.
This is the core process at Standard-Metallwerke. The tubes are worked gradually using outer and inner tool. This generally reduces the outside diameter and the thickness of the wall. At the same time, the crystalline structure of the metal itself is modified.
Depending on customer requirements, many tubes require a straightening process to maintain the required level of straightness. Different straightening or stretching machines are used for this purpose.
Washing and degreasing
Prior to subsequent production steps or in case of intermediate annealing, there is a cleaning process to remove the lubricants and oils necessary during drawing from the surface and inside the tubes. These would otherwise lead to contamination on the material that are not desirable functionally or decoratively.
In many cases, drawing is followed by a heat treatment, partially in several steps. We have different furnaces for this that heat the tubes either in a pass-through procedure or in a chamber.
The tubes are then cut to the requested length, either as the so-called manufacturing length in a defined length range or as a fixed length with tight tolerances. For manufacturing lengths, a chip-free choping process is often used. Chip-free procedures that can be used for fixed lengths are orbital cutting and shearing. The tubes can also be sawn, which necessitates subsequent deburring and possibly washing.
The most frequently used type of forming is the preforming of geometries that make it possible to slide on hoses or attach connectors.
This is the manufacture of tubes in different bending procedures. Tubes made of stainless steel, steel and aluminium are processed according to customer specifications. Cross sections from d=5mm to d=35mm
Welding and brazing
This is the manufacture of connections using welding or brazing procedures according to customer specifications.
Assembly of subassemblies made of tubes and different components as for example UBL according to the customer’s drawings.
Straight tubes are usually packed in wooden crates or racks; fixed lengths can be packed in pallet cages, cartons or returnable containers. For assemblies, custom-made inserts are used to prevent damage during transport.